Rockwell RCV144ACx, Справочник по командам

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AT Command Reference Manual
1048 6-3
4. All Class 2 commands are assumed to be the final command on a command line. Additional characters will be ignored.
5. An ERROR message will be generated if any of the following conditions occur:
a. A Class 1 command is received while in Class 2.
b. A Class 2 command is received while in Class 1.
c. A Class 1 or Class 2 action command is received while in data modem mode.
d. A Class 2 read-only parameter is given the “=” form of a +F command (e.g., AT+FAXERR=5).
e. A Class 2 action command is given the inappropriate “=” or “=?” form (e.g., AT+FDR=?).
6.1.2 Serial Port Speed and Flow Control
During fax mode, the DTE-DCE port speed is 19200 bps.
The DCE provides a speed buffer of 1024 bytes and provides the DC1/DC3 (XON/XOFF) or RTS/CTS method of controlling
the data into the buffer. This flow control is controlled by the &K3 or &K4 command.
This method of data flow control is available only for DTE to DCE direction of data. There is no provision for data flow control
from DCE to DTE.
Data Stream Termination
The DCE exchanges streams of data with the DTE while executing data transfer commands. These data streams use the
termination described in Section 3.2/ISO 2111.
The ASCII <DLE> character (016) is used as a special character to shield special characters. The <DLE><ETX> character
pair (<106><003>) is used to mark the end of a stream. The following patterns are used:
any data...<DLE><ETX> end of stream
any data...<DLE><DLE> single <DLE> in data
any data...<DLE><any byte> delete <DLE><any byte>
DTE to DCE Streams
The DCE filters the data stream from the DTE, and removes all character pairs beginning with <DLE>. The DCE recognizes
<DLE><ETX> as the stream terminator. The DCE recognizes <DLE><DLE> and reinserts a single <DLE> in its place.
The DTE must filter stream data to the DCE, and insert extra <DLE> characters ahead of data.
DCE to DTE Streams
The DTE must filter the data stream from the DCE, and remove all character pairs beginning with <DLE>. The DTE must
recognize <DLE><ETX> as the stream terminator. The DTE must recognize <DLE><DLE> and reinsert a single <DLE> in its
place.
The DCE filters stream data to the DTE, and inserts extra <DLE> characters ahead of data.
6.1.3 Auto Answer
The DCE can answer as a data DCE or as a fax DCE. It can answer the call adaptively, i.e., it can determine whether the
call is 'data' or 'fax'. The +FAA parameter controls this feature. Fax adaptive answer operates only when +FCLASS=0.
AT+FAA=1 ; Auto answer as a facsimile or a data modem depending on the call
CONNECT XXXX ; DCE status response if data call
+FCON ; DCE status response if fax call
6.1.4 Identification of T.30 Options
Group 3 devices negotiate session parameters in DIS, DCS, and DTC frames. These parameters are defined in Table 6-2.